The invention relates to an arrangement for driving accessories of an internal combustion engine such as a water pump or a fan by means of a V-belt drive operated by the engine crankshaft.
It is generally known to connect the fan directly to the crankshaft or to an extension of the crankshaft in order to drive the fan directly. Additional engine accessories or aggregates such as the water pump, a generator, an AC compressor or other auxiliary aggregates are generally driven by a V-belt drive using one belt for all aggregates.
DE 195 11 702 A1 and DE 24 23 746 C2 show that it is also known to drive the fan by way of the water pump shaft wherein generally the water pump is connected to the crankshaft by means of a V-belt drive. The fan is arranged co-axially with the pump shaft and is driven thereby by way of clutch.
It is, however a disadvantage that the forces that is the load generated by the fan acts on the whole drive consisting of the belt drive and the aggregates driven thereby. In addition, the speed of the fan is determined by the engine speed or, respectively, the water pump speed.
It is therefore the object of the present invention to provide an arrangement of the type referred to above, wherein however, the fan transmission ratio is independent of the basic belt drive and wherein the forces and loads generated by the fan are not taken up by the whole basic belt drive.